Quadruple Screen-Printed Carbon Electrode (4WE-SPCE) as Flexible Electrochemical Biosensors, CFEBQSPCE

A Quadruple Screen-Printed Carbon Electrode (4WE-SPCE) integrates four independently addressable carbon working electrodes (WE1–WE4) with a shared counter electrode (CE) and reference electrode (RE) on a single planar strip (typically alumina ceramic or PET). This 6-lead configuration enables four-target multiplexing, in-situ multi-point calibration, or high-confidence replicate testing within a single micro-droplet (50–100 uL).

The Main Operating Modalities: (1) Quadruplex Multiplexed Panels: Functionalizing each carbon disk with a unique biological capture receptor or nanomaterial catalyst. Multiplexed Biomarker Panels: Simultaneous detection of cardiac panels (cTnI, NT-proBNP, D-Dimer, and Myoglobin) or multi-pathogen panels (e.g., SARS-CoV-2, Flu A, Flu B, RSV) in clinical point-of-care diagnostics. Environmental Heavy-Metal Screening: Concurrent or selective stripping detection of Zn^{2+}, Cd^{2+}, Pb^{2+}, Cu^{2+}. (2) Dual-Target with Dual-Reference Architecture: WE1 & WE2 (Target Channels): Specific biosensing receptors for two distinct disease markers. WE3 (Negative Control): Blocked with non-specific proteins (e.g., BSA or scrambled oligonucleotides) to quantify and subtract complex matrix fouling in whole blood, saliva, or raw wastewater. WE4 (Internal Calibrant): Surface-tethered with an invariant redox active tag (e.g., ferrocene or methylene blue) to normalize for temperature fluctuations, active area variations, or bulk viscosity shifts. (3) On-Chip Statistical Replicates (n=4): Coating all four electrodes with identical sensing films. A single run produces four independent Faradaic measurements, automatically yielding an on-chip relative standard deviation (RSD) to flag outlier readings.

References:

1. H. Beitollahi, et al., Applications of electrochemical sensors and biosensors based on modified screen-printed electrodes: a review, Anal. Methods (2020) 12 (12): 1547–1560.
2. Keiichiro Yamanaka, et al. Printable Electrochemical Biosensors: A Focus on Screen-Printed Electrodes and Their Application, Analytical and Bioanalytical Chemistry, 2005, 382, 884–886.